Safety valve for subsurface conduit strings



April 5, 1960' E. H. CLARK, JR

SAFETY VALVE FOR SUBSURFACE CONDUI'I STRINGS Filed Feb. 13, 1956.EZfi/Vffffl 62 A066, Je.

INVENTOR.

BY m M )v Ww/ flrraewa s:

Califl, assignor to Baker Earnest H. (liar-k, lira, Downe Califi, acorporation of Oil T oois, inn, Los Angeles, California ApplicationFebruary 13, 1956, Serial No. 564,952 7 Claims. (Cl. 137-498) Thepresent invention relates to valve devices, and more particularly tovalve devices for controlling flow of fluids in well bores.

An object of the present invention is to provide an improved valvedevice for automatically shutting off the flow oi fluids in a well borewhen the rate of flow becomes excessive.

Another object of the invention is to provide a valve device forautomatically shutting off the flow of fluids in a well bore when therate of flow becomes excessive, in which a straight flow path for thefluid is present in the valve device when in open condition, therebyminimizing erosive wear on the parts by the flowing fluid.

A further object of the invention is to provide a valve device thatcloses automatically when fluid flow in the well bore becomes excessive,the valve device being adapted for incorporation in a tubular stringdisposed in the well bore and being capable of transmitting torque, inorder that the tubular string can be operated to efiect its connectionor dsconnection to and from another apparatus in a well bore, such as awell packer.

An additional object of the invention is to provide a simple andrelatively inexpensive valve apparatus capable of being disposed in awell bore for the purpose of controlling flow of fluids therein.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. Such form is shown in the drawingsaccompanying and forming part of the present specification. This formwill now be described in detail, for the purpose of illustrating thegeneral principles of the invention; but it is to be understood thatsuch detailed description is not to be taken in a limiting sense, sincethe scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure l is a longitudinal section through an embodiment of theinvention, with the valve device disposed within a well casing and beingin open condition;

Fig. 2 is a view similar to Fig. 1, with the valve device in closedposition;

Fig. 3 is a cross-section taken along the line 3--3 on Fig. 1;

Fig. 4 is a cross-section taken along the line 4-4 on Fig. l.

The valve device A illustarted in Figs. 1 to 4, inclusive, of thedrawings is adapted to be incorporated in a string of production tubingB disposed in a well casing C, the production tubing extending to thetop of the well bore. The lower portion of the valve device may beconnected to lower production tubing D, that can be secured to a lowerwell packer (not shown) anchored in packed-E condition in the wellcasing.

The valve device A includes an outer housing structure 19 consisting ofan upper head 11 threadedly secured to the lower end of the string ofproduction tubing B extending to the top of the hole. This head isthreadedly attached to an upper housing section 12, which is, in

States Patent 0 turn, threadedly secured to an intermediate housingportion or coupling 13 threaded into a lower housing section or cylinder14. This lower housing section is threadedly attached to a tubular sub15, which may be threaded onto a lower section of tubing D forming partof a lower tubular string extending and connected to a lower well packer(not shown).

Integral with and depending from the housing head 11 is an inner tubularhousing portion 16 having an annular valve seat 17 provided by its lowerend. This valve seat is adapted to be engaged by a flapper valve head18, to prevent upward flow of fluid through the valve apparatus and intothe production tubing B thereabove. This flapper valve head is pivotallymounted on a hinge pin 19 secured to a leg 29 suitably welded, orotherwise attached, to the inner housing member 16.

The ability of the valve head 18 to swing upwardly into engagement withits companion seat 17 is dependent upon the position of a valveactuating sleeve 21, which is adapted to cam and hold the valve head 18completely to one side of the passage 22 through the inner housingmember, or which can permit the valve head to swing upwardly intoengagement with its seat 17. This valve sleeve 21 is severed, orsubstantially cut away, at one side to permit the valve head to assume adepending position, such as disclosed in Fig. 1. It has upper holdingsurfaces 23 adapted to engage the marginal portion of the valve head 18,to hold the latter completely to one side of the passage 22 through theinner housing portion, these holding surfaces merging into downwardlyand inwardly tapering cam surfaces 24 which can cam the valve head 18from a closed to an open position when the valve actuating sleeve 21moves downwardly with respect to the head, as described hereinafter.

The upper portion 25 of the actuating sleeve has an internal diameterslightly greater than the external diameter of the inner housing portion16, to enable the sleeve to slide over the latter. The upper portion 25of the sleeve opens downwardly into an enlarged portion 26, whichterminates in an upwardly directed holding shoulder 27 adapted to engagethe back side 23 of the valve head 18 when the latter engages the valveseat 17, thereby limiting upward movement of the sleeve 21 within thehousing 1!). Proper orientation between thecam and holding surfaces 24,23 of the sleeve 21 and valve head 18 is maintained by welding, orotherwise suitably securing, a key element 29, or the like, to the innerhousing member 16 opposite the leg 29 on which the valve head ispivot-ally mounted, this key element being received within alongitudinally extending slot 30 in the valve sleeve that extendsdownwardly from its upper end almost to its lower portion 31. This lowerportion bridges the slot 39 and integrates the two halves or mainportions of the sleeve 21.

The position of the sleeve 21 upwardly of the housing 10, in which thevalve head 18 is engaged with the seat 17, or downwardly of the housing,in which the valve head 18 is maintained in its fully open position withrespect to the seat 17, depends upon the rate of fluid flow through atubular mandrel 32 slidably mounted in the housing. The upper end ofthis mandrel 32 is connected to the lower portion of the valve actuatingsleeve 21 through the agency of a two-piece coupling ring 33. This ringhas an outside diameter substantially equal to the inside diameter ofthe upper housing section 12, and

is provided with a lower inwardly directed flange 34 received with aperipheral 36 received within a peripheral groove 37 in the valveactuating sleeve. It is evident that the coupling ring 33 secures thesleeve 21 and mandrel 32 together for joint longitudinal movement withinthe housing 10.

groove 35 in the tubular man-. drel, as well as with an upper inwardlydirected flange nular cylinder space terminates at an inwardly directed.

flange 42 of the intermediate coupling or housing, which slidablyengages the periphery 4d of the mandrel. Intercommunication is providedbetween the central passage 43 through the tubular mandrel 32 and theannular cylinder space 4-1 by means of a plurality of ports 44 extendingthrough the mandrel wall.

The valve head 18 may have a rubber or rubber-like 0 ring 45, orcorresponding seal ring, mounted in its forward sealing face 46 andadapted to engage the valve seat 17, to prevent leakage between thevalve head and.

the seat when the valve is in closed position. The piston 38 may have a.rubber or rubber-like O ring 146, or corresponding seal ring, disposedin a piston ring groove 47, which makes slidable sealing engagement withthe cylinder wall 39. Similarly, the internal coupling flange 42 mayhave an internal groove 48 therein containing a rubber or rubber-like 0ring 49, or corresponding seal ring, adapted to slidably seal with theperiphery 40 of the mandrel 32. The seal element 46 on the piston andthe seal ring 49 in the flange 42 need not be used, proaes'aaei 7 1 7 ipressure, whereas the fluid in the mandrel passage 43' itself must havea greater velocity, since the mandrel passage area R is less than thearea S through the housing therebelow, with a consequent reduction inpressure the mandrel 32. Inasmuch as the pressure in the mandret passage43 has been lowered, the pressure in the annular cylinder space 41between the mandrel and the cylinder wall 39 will also be lowered,producing a pressure differential across the piston 38 tending to movethe piston, the tubular mandrel 32 and valve actuating sleeve 21connected therewith in an upward direction within the housing 16. Suchpressure dilferential, however, is resisted by the compression spring50, which will pre vent any movement whatsoever until the pressuredifferential achieves a value sufiicient to overcome the force of thespring.

Normally, the valve apparatus is in the open position disclosed in Fig.1, in which the rate of fluid flow through the apparatus is insuflicientto produce a pressure diflierential across the piston 38 to overcome thecompressive force of the resisting spring 50. However,- should the flowof fluid be increased to a considerableextent, as, for example, by thebreaking of the surface vided the piston 38 makes a close sliding fitwith the cylv inder wall 39 and the flange 42 makes a fairly closesliding fit with the periphery 40 of the mandrel, inasmuch as theapparatus will operate properly despite the presence of some minorleakage around the piston 38 and between the inner flange 42 and theperiphery 40 of the Y mandrel 32.

The mandrel 32 is urged in a downward direction within the housing It tocarry the actuating sleeve 21 down with it, by a helical compressionspring 50 disposed in the annular space 41 the lower end of the springbearing against the piston'33 and the upper end of the spring againstthe lower end of the coupling 13. The extent of downward movement of themandrel 32 and actuating sleeve 21 under the influence of the spring 50is limited by engagement of the two-piece coupling ring 33 with theupper end of the intermediate housing member or coupling 13, whichfunctions as a stop member.

When the mandrel 32 and actuating sleeve 21 are in their lowermostposition within the housing 10, the holding cam surfaces 23 are inengagement with the valve head 18, to hold it completely to one side ofthe passage 22, 43 through the valve apparatus. When the mandrel andactuating sleeve move upwardly, as hereinafter described, the extent ofsuch upward movement is limited by engagement of the valve head 18 withthe valve seat 17 and of the holding shoulder 27 of the valve sleevewith the back or rear side 28 of the valve head. In shifting upwardly,the valve sleeve 21 has a portion 51 which will engage the rear side 28of the valve head 18 and swing it into the path of fluid flowingupwardly through the valve apparatus, the fluid carrying the valve head18 upwardly to its fully closed position against its'companion seat 17 7w It is to be noted that the passage 43 through the piston 38, tubularmandrel 32, and actuating sleeve 21 is unrestricted, and that suchunrestricted passage can continue upwardly through the inner housingportion 16. Thus, when the valve is in the fully open position shownconnections at the top of the well bore, the velocity of flow throughthe mandrel will be proportionately increased, proportionatelydecreasing the static pressure within the annular cylinder space 41above the piston 38. The pressure difierential across the piston maythereby be increased to an extent sufficient to overcome the force ofthe spring 5%, the pressure then shifting the mandrel 32 and theactuating sleeve 21 upwardly, the actuating sleeve sliding over theinner housing portion 16 and causing its lower portion 51 to engage theback side 28 of the valve head 18 and shift it toward the valve seat 17,the fluid flowing through the apparatus then carrying the valve headupwardly into engagement with the valve seat 17, closing the latteragainst upward flow of fluid. The extent of upward movement of the valvein Fig. 1, fluid can flow in an unobstructed and unrestricted mannerthrough the valve apparatus, which will minimize erosion wear of thefiuid or fluent material on the valve parts. The area R through thetubular man drel passage 43, however, is substantially less than thearea .S of the cylinder 14 below the piston or mandrel head 38.Accordingly, the fluid in the cylinder 14 below the piston38 will have acertain velocity and a certain sleeve 21 will be limitedby engagement ofits holding shoulder 27 with the rear 'face 28 of the flapper valvehead. The flow through the apparatus A is shut off completely, whichwill also eliminate the pressuredifierential across the piston 38.Despite this fact, the spring 50, which is now in a highly compressivestate, such as disclosed in Fig. 2, cannot shift the mandrel 32 andsleeve 21 back to their "initial position to open the flapper valve 18,since the relatively high pressure in the mandrel 32 and in the lowertubing string D, as comparedwith the pressure in the production tubing Babove the valve apparatus, will hold the valve head 18 against its seat17 and prevent the cam faces 24 from shifting the valve head from theseat.

Should it be desired to again place the valve apparatus A in an opencondition, pressure'of the proper amount is imposed on the fluid in theproduction tubing B, this pressure acting on the seating face 46 of thevalve head 18, shifting it downwardly from the seat 17, therebyequalizing the pressure above and below the valve head 18. Thisequalizing of pressure permits the spring 50 to shift the mandrel 32 andactuating sleeve 21 downwardly, the cam surfaces 24 of the actuatingsleeve moving the valve head 18 completely to its open position,whereupon the holding surfaces 23 slide across the marginal portion ofthe sealing face 46 of the valve head to insure its retention in itsfully open position out of the path of fluid flow through the valveapparatus. Upward flow of fluid through the valve apparatus A andproductiontubing D,

B is again permitted to take place.

head adjacent to said seat; tubular means movable in said housingupstream of said seat and engageable with said head to determine itsengagement with said seat; said tubular means having a longitudinalpassage from which fluid can flow past said head and into said outletpassage when said head is disengaged from said seat, the area of saidlongitudinal passage being less than the internal area of said housingupstream of said tubular means; said tubular means having piston meansthereon slidable along said housing and subject to the pressure of fluidin said housing upstream of said tubular means; said tubular meanshaving a port upstream of the outlet end of said longitudinal passageestablishing communication between said longitudinal passage and theexterior of said tubular means downstream of said piston means tosubject the downstream side of said piston means to the fluid pressurein said longitudinal passage.

2. In a control valve: a housing having an outlet passage therethroughsurrounded by a valve seat; a valve head movable laterally in saidhousing into engagement with said seat to restrict flow of fluid in saidpassage and laterally from engagement with said seat to permit flow offluid in said passage; means for disposing said valve head adjacent tosaid seat; tubular means movable in said housing upstream of said seatand engageable with said head to determine its engagement with saidseat; said tubular means having a longitudinal passage from which fluidcan flow past said head and into said outlet passage when said head isdisengaged from said seat, the area of said longitudinal passage beingless than the internal area of said housing upstream of said tubularmeans; said tubular means having piston means thereon slidable alongsaid housing and subject to the pressure of fluid in said housingupstream of said tubular means; said tubular means having a portupstream of the outlet end of said longitudinal passage establishingcommunication between said longitudinal passage and the exterior of saidtubular means downstream of said piston means to subject the downstreamside of said piston mean to the fluid pressure in said longitudinalpassage; and spring means engaging said tubular means to urge saidtubular means in a direction upstream of said housing.

3. In a control valve: a housing having an outlet passage therethroughsurrounded by a valve seat; a valve head movable laterally in saidhousing into engagement with said seat to restrict flow of fluid in saidpassage and laterally from engagement with said seat to permit flow offluid in said passage; means for disposing said valve head adjacent tosaid seat; a tubular member slidable longitudinally in said housingupstream of said seat and engageable with said head to determineengagement of said head with said seat; said tubular member having alongitudinal passage from which fluid can flow past said head and intosaid outlet passage when said head is disengaged from said seat, thearea of said longitudinal passage being less than the internal area ofsaid housing upstream of said tubular member; a piston secured to saidtubular member and slidable along said housing at said internal area;said tubular member having a portion of less external diameter than theexternal diameter of said piston and slidable along said housingdownstream of said piston to provide a substantially confined annularspace around said tubular member between said portion and housing; saidtubular member having a port upstream of the outlet end of saidlongitudinal passage establishing communication between saidlongitudinal passage and said annular space.

4. In a control valve: a housing having an outlet passage therethroughsurrounded by a valve seat; a valve head movable laterally in saidhousing into engagement with said seat to restrict flow of fluid in saidpassage and laterally from engagement with said seat to permit flow offluid in said passage; means for disposing said valve head adjacent tosaid seat; a tubular member slidable longitudinally in said housingupstream of said seat and engageable with said head to determineengagement of said head with said seat; said tubular member having alongi tudinal passage from which fluid can flow past said head and intosaid outlet passage when said head is disengaged from said seat, thearea of said longitudinal passage being less than the internal area ofsaid housing upstream of said tubular member; a piston secured to saidtubular member and slidable along said housing at said internal area;said tubular member having a portion of less external diameter than theexternal diameter of said piston and slidable along said housingdownstream of said piston to provide a substantially confined annularspace around said tubular member between said portion and housing; saidtubular member having a port upstream of the outlet end of saidlongitudinal passage establishing communication between saidlongitudinal passage and said annular space; and spring means in saidannular space engaging said piston to urge said piston and tubularmember in an upstream direction within said housing.

5. In a control valve: a housing having an outlet passage therethroughsurrounded by a valve seat; a valve head adapted to engage said seat torestrict flow of fluid in said passage, tubular means movable in saidhousing upstream of said seat and operatively connected to said head todetermine its engagement with said seat; said tubular means having alongitudinal passage from which fluid can flow past said head and intosaid outlet passage when said head is disengaged from said seat, thearea of said longitudinal passage being less than the internal area ofsaid housing upstream of said tubular means; said tubular means havingpiston means thereon slidable along said housing and subject to thepressure of fluid in said housing upstream of said tubular means; saidtubular means having a port upstream of the outlet end of saidlongitudinal passage establishing communication between saidlongitudinal passage and the exterior of said tubular means downstreamof said piston means to subject the downstream side of said piston meansto the fluid pressure in said longitudinal passage; said valve headbeing pivotally carried by said housing; said tubular means including anactuator engageable with said valve head to swing said head from saidseat completely to one side of said outlet passage in response tomovement of said tubular means in an upstream direction within saidhousing.

6. In a control valve: a housing having an outlet passage therethroughsurrounded by a valve seat; a valve head adapted to engage said seat torestrict flow of fluid in said passage, tubular means movable in saidhousing upstream of said seat and operatively connected to said head todetermine its engagement with said seat; said tubular means having alongitudinal passage from which fluid can flow past said head and intosaid outlet passage when said head is disengaged from said seat, thearea of said longitudinal passage being less than the internal area ofsaid housing upstream of said tubular means; said tubular means havingpiston means thereon slidable along said housing and subject to thepressure of fluid in said housing upstream of said tubular means; saidtubular means having a port upstream of the outlet end of saidlongitudinal passage establishing communication between saidlongitudinal passage and the exterior of said tubular means downstreamof said piston means to subject the downstream side of said piston meansto the fluid pressure in said longitudinal passage; said outlet passageand longitudinal passage being coaxial; said valve head being pivotallycarried by said housing; said tubular means including an actuatorengageable with said head, in re sponse to movement of said tubularmeans in an upstream direction, to swing said head from said seat to oneside of said housing completely out of the path of fluid flow throughsaid passages.

7. In a control valve: a housing having an outlet passage therethroughsurrounded by a valve seat; a valve head adapted to engage said seat torestrict flow of fluid in said passage; a tubular member slidablelongitudinally in said housing upstream of said seat and operativelyconnected, to saidhead to determine engagement of said head with saidseat; said tubular member having a longitudinal passage from which fluidcan flow past said head and into said outlet'passage when said head isdisengaged irom said seat, the area of said longitudinal passage beingless than the internal area of said housing upstream of said tubularmember; a piston secured to said tubular member and slidable along saidhousing at said internal area; said tubular member having a portion ofless external diameter than the external diameter of said piston andslidable along said housing downstream of said piston to provide asubstantially confined annular space around said tubular member betweensaid portion and housing; said tubular member having a port upstream ofthe out let end of said longitudinal passage establishing communicationbetween said longitudinal passage and said annular space; said outletpassage and longitudinal passage being coaxialj'said valve head beingpivotally carried by said housing; and an actuator Connected to saidtubular member, said actuator being engageable with said head, inresponse to movement of said tubular member in an upstream direction, toswing said head from said seat to one side of said housing completelyout of the path of fluid through said passages. 7

References Cited in the file of this patent v UNITED STATES PATENTS2,138,719 Wright .NOV. 29, 1938 2,373,034 Laird Apr. 3, 1945 2,411,392Saville 'Nov. 19, 1946 2,583,295 Greer Jan. 22, 1952 2,601,654 'WrightJune 24, 1952

